Which federal excise tax is no longer imposed?

The federal excise tax on air travel is no longer imposed due to changes in tax laws and regulations over the years. Initially established to fund airport infrastructure and enhance air travel services, this tax was repealed as government priorities evolved and funding mechanisms were restructured. The removal of this tax reflects legislative adjustments aimed at stimulating the airline industry and making air travel more affordable for consumers.

In contrast, the taxes on wagering and alcohol remain in effect. Wagering taxes are collected to regulate and fund gambling activities, while alcohol excise taxes serve both regulatory and revenue-generating purposes, remaining integral to the federal tax system. The option "None of these" would imply that all stated taxes are still in place, which is not the case in regards to air travel. Therefore, the correct choice highlights the unique circumstance of the air travel tax's repeal in relation to the other options listed.